Motor control.



No. 767,692. PATENTED AUG. 16, 1904. J. D. IHLDER. MOTOR CONTROL.

APPLICATION FILED MAY 8, 1902. N0 MODEL.

2 SHBETSSHEET 1.

N [Jnvamfor I No. 767,692. PATENTED AUG. 16, 1904 j V J. D. IHLDER.

MOTOR CONTROL.

APPLICATION FILED MAY 8, 1902.

N0 MODEL.

2 SHEETSSHEET 2 (1n ucul'ozf d 41% Qvil'neaoes 1/ UNITED STATES Patented August 16, 1904.

PATENT OFFICE.

JOHN D. IHLDER, OF YONKERS, NEW YORK, ASSIGNOR TO OTIS ELEVA- TOR COMPANY, OF EAST ORANGE, NElV JERSEY, A CORPORATION OF NEW JERSEY.

MOTOR CONTROL.

SPECIFICATION forming part of Letters Patent No. 767,692, dated August 16, 1904. Application filed May 8, 1902. Serial No. 106,483. (No model.

To all whom it may concern.-

Be it known thatI, J OHN D. IHLDER, a citizen of the United States, residing at Yonkers, in the county of estchester and State of New York, have invented certain new and useful Improvements in Motor Control, of which the following is a specification.

My invention relates to motor control; and its objects are primarily to enable an electric motor to be automatically controlled in a sim ple and convenient manner, which reduces the liability of injury to the motor and prevents the starting-current from rising beyond a predetermined amount.

Further objects of my invention will hereinafter appear; and to these ends my invention consists in the system of motor control devised for carrying out the above objects and having the general mode of operation, substantially as fully described, and shown in the accompanying specification and drawings, in which Figure 1 is a diagrammatic view of circuits and apparatus embodying my invention. Fig. 2 is a diagrammatic View embodying a modified form of my invention, and Fig. 3 is a diagrammatic view of another modification.

Referring to the drawings, A represents a motor which may be of any suitable type, but shown in this instance as a compound-wound motor adapted to be connected in circuit with the supply-mains (indicated by and and provided with a series field-winding B and a shunt field-winding O, the shunt-field being connected to the mains at the points a and Z) in Figs; 1 and 2 and connected between the point a on the reversing-switch V and the point 6 in Fig. 3.

A suitable switch D is arranged to control the admission of current to the motor-armature, and the throwing of the switch-lever 0 into contact with contacts (Z and 6 will first complete the circuit of an electromagnet E, connected across the mains and controlling contacts f in the main armature-circuit. The

energizing of magnet E closes contacts f and completes the circuit to the motor through when the switch D is closed.

resistance R, the series field-winding B, and a magnet F in series with the armature.

A controlling-magnet G is connected across the mains between the point 6 and contact 0 of switch D and receives the line-potential As shown in this instance, the magnet G is provided with a plurality of cores 1 2 3 in Figs. 1 and 2 and 1, 2, 3, and 4 in Fig. 3, controlling armatures 5, 6, 7 and 8, arranged at different distances from the cores. According to the arrangement diagrammatically illustrated, armature 5 is nearest to its core, and the otherarmatures are arranged at gradually-increasing distances from the cores, so that armature 5 will be attracted against core 1 at a lower magnetizing force than the others, and the remaining armatures will be actuated at higher magnetizing forces. Springs of variable tensions might be used instead of placing the armature at different distances from the cores, as shown. According to the connections shown, as armatures 5, 6, and 7 are actuated the resistance R and the series field B are short-circuited.

Connected in circuit with the magnet G is a resistance S, around which is arranged a short circuit in which are contacts 71 controlled by magnet F in series with the main armature circuit. That one of contacts h which is movable is controlled by a spring which will close the contacts when the current in magnet F reduces to a given amount. The armatures 5, 6, and 7 are so adjusted that they are not actuated when the resistance S is included in the circuit of magnet G, which may be termed an accelerating-magnet.

The closing of the main circuit at contacts f through the operation of magnet E admits the maximum starting-current to the motor. The energizing of magnet F causes the opening of the normally closed contacts 7t, thereby throwing resistance S into series with the magnet G before the first armature 5 can be actuated. hen the current has decreased after starting a predetermined amount, the movable one of contacts It will be released and the resistance S short-circuited. This allows the magnetization of magnet G to increase sufliciently to cause core 1 to attract armature 5 and short-circuit a portion of the resistance R. The current increases again to a maximum, magnet F opens the contacts h, and the next armature 6 is not actuated until the contacts have again closed upon a sufficient reduction of current. In stopping, the circuit of magnet G is broken first at the short contact 6, thereby throwing the resistance back into circuit. It will readily be seen that the apparatus described prevents the motor starting with more than apredetermined amount ofcurrent.

The diagram of Fig. 1 applies more particularly to the starting of a motor. When a motor is raising or lowering a load, as in elevator-work and must be quickly and gently stopped, I prefer to. use magnets which complete an armature-circuit containing resistance, which resistance is gradually and automatically short-circuited to stop the motor by the closure of the magnet-contacts.

In Fig. 2 when switch D is thrown to stop the motor the circuit of magnets G and E is broken, thereby breaking the armature-circuit at contacts f, and when switch-lever c is moved into contact with contact is acircuit is completed through magnet H which closes an armature-circuit at the contacts p. This armature-circuit is connected across the armature, as shown from the point Z to the point m, and includes the coil 11, differentially around magnet I, and also includes the stopping resistance J. The magnet I is provided with a plurality of cores 9 and 10, controlling armatures 11. and 12, connected to short-circuit resistance J, as the armatures are actuated. A second winding 0, connected in shunt to the winding 11, is provided upon the magnet I and wound to oppose the coil n.- After the motor-circuit is broken at contacts f the revolving armature furnishes power for the coils a and 0 of magnet I, which counteract each other at first and prevent the normally open armatures 11 and 12 from closing until the current is sufficiently reduced to allow the shunt-coil 0, which is arranged to be slower acting than coil n, to come up to strength and first close contact 12, which is arranged closer to its core than contact 1 1, and then close contact 11, thus short-circuiting the resistance J and bringing the motor to a stop gradually.

In Fig. 3, as in Figs. 1 and 2, the heavy lines represesent the armature-circuits and the light lines represent the controlling-circuits for the motor, and in Fig. 3 a modified form of apparatus is shown, operating like that shown in Figs. 1 and 2, but including means V for reversing the motor and controlling its operation from a distance, as from the car of an elevator or from a station or landing. The hand operating-switch D is provided with a lever 0, central contacts is, and side contacts (Z a and d a, with circuit-wires connected to is completed.

the lever and contacts and including the reversing-magnets E E and controlling-magnet H. All the motor-circuits and controllingcircuits are connected to and from the binding-posts 15, 16, 17, 18, 19, and 20. Each of the cores 13 and 14 of the magnets E E is provided with arms carrying contacts 23 24 25 26 and 31 32 33 34, cooperating with contacts 21 22 27 28 and 29 30 36. Suitable connections and cross connections are made between the contacts mentioned and the motor and the mains for reversing the current through the armature according as one or the other of the magnets E or E is energized to actuate a core 13 or 14. If magnet E is en ergized by throwing the switch-arm C in one direction and core 13 is raised, the contacts 25 and 26 are in contact with the upper lefthand contacts 21 and 22, and as the magnet E is not energized when E is energized the weight of the core 14 and its contacts will cause contacts 31 and 32 to rest upon the lower right-hand contacts 35 and 36. Thus the circuit of the motor for one direction of rotation If the opposite direction is desired, the magnet E would be energized, thereby raising the core 14 by throwing the switcharm C in the opposite direction, when magnet E would be unenergized. The contacts 33 and 34 would therefore bear against the upper right-hand contacts 29 and 30,'while the contacts 23 and 24 would rest upon the lower lefthand contacts 27 and 28, thus closing the circuit of the motor for the opposite direction of rotation. Both sets of movable contacts are normally in their lowest positions-that is, where they rest upon the contacts 27, 28, 35, and 36. The construction and operation of this electromagnetic reversing-switch are the same as that of the switch fully disclosed in my Patent No. 704,336, issued July 8, 1902. In the switch described in that patent means are shown for preventing both the lower sets of contacts from being closed at once, and the switch diagrammatically represented in the present application is to be so understood as to operating, for the closure of both the lower sets of contacts at the same time would shortcircuit the motor. Upon moving switch-blade 0 to the lefti'or instance, upon contacts (Z ea circuit will be closed through magnet E from a point 40 on the positive main through blade 0 and contact (Z to the negative main at 41. Magnet E will raise core 14 and close contacts 29 33 and 30 34, the lower contacts 23 27 and 24 28 being already closed by the weight of the core 13. A circuit will then be completed to the motor from the positive main at the switch W through contacts 29 33 and 24 28 to and through the motor, thence through contacts 23 27 to resistance R and series field B, thence through magnet F and to the negative main. The accelerating-magnet G is shown, as before, connected in shunt to the line from a point 6 to the switch-contacts e e, and the operation of this magnet is the same as that described for the same magnet in Figs. 1, 2. The magnet F controls contacts /L in the short circuit about resistance S in the circuit of magnet G, and in this instance said magnet G is provided with cores 1, 2, 3, and 4, which short-circuit the resistance R and series field B as they are actuated. The differentially-wound magnet I operates as before described, and its circuit is controlled by contacts 9, actuated by a magnet H, connected to be energized by contact of switch-lever 0 upon contact is when switch at is operated to stop the motor. WV hen magnet H becomes energized, closing contacts p, and armature circuit is completed from a point Z through series winding 11 of magnet I, from thence through stopping resistance J and contacts p to the point on on the armature-circuit. The operation of short-circuiting the stopping resistance J is as hereinbefore described.

WVithout limiting myself to the construction shown and described, I claim 1. The combination with a motor, ofa controlling-magnet operated at line-potential, and means controlled by variations of motor-current for varying the ampere-turns of said controlling-magnet, substantially as and for the purposes set forth.

2. The combination with a motor, of acontrolling device operated at line-potential, and means controlled by variations of motor-current connected to vary the resistance of the circuit of said controlling device, substantially as and for the purposes set forth.

3. The combination with a motor,- of a controlling-magnet provided with a plurality of cores and operated at line-potential, and means controlled by variations of motor-current for varying the strength of the cores of said controlling-magnet, substantially as and for the purposes set forth.

4. The combination with a motor, of a controlling-magnet having a plurality of cores and operated at line-potential, a starting resistance controlled by said magnet, and means controlled by variations of motor-current for varying the strength of said controlling-magnet, substantially as and for the purposes set forth.

5. The combination with a motor, of a controlling-magnet having a plurality of cores,.a resistance in series with the controlling-magnet, a shunt around said resistance, and means controlled by variations of motor-current for varying the strength of said controlling-magnot and thereby controlling the resistance, substantially as and for the purposes set forth.

6. The combination with a motor, of a controlling-magnet having a plurality of cores and operated at line-potential, a resistance in series with the controlling-magnet, a shunt around said resistance, and a magnet in the motor-circuit controlled by variations of motor-current and varying the strength of said controlling-magnet, substantially as and for the purposes set forth.

7. The combination with a motor, and a resistance in the circuit of the motor, of a controlling-magnet having a plurality of cores, and operated at line-potential, means controlled by variations of motor-current for varying the strength of said controlling-magnet, a switch, a circuit controlled by said switch, and means in said circuit for closing the circuit of the motor, substantially as described.

8. The combination with a motor having resistance and a magnet in the motor-circuit, of a controlling-magnet operated at lino-potential, a resistance in series with said magnet, and a shunt around the resistance controlled by variations of motor-current, substantially as and for the purposes set forth.

9. The combination with a motor, resistance, and a magnet in the motor-circuit, of a controlling-magnet operated at line-potential, a circuit including a third magnet for closing said motor-circuit, and a switch controlling the circuit of said third magnet and said controlling-magnet, substantially as and for the purposes set forth.

10. The combination with a motor, of a stopping resistance, and a doubly-wound electromagnet controlling said resistance, one of the coils of said magnet being slower acting than the other, substantially as described.

11. The combination with a motor, of a resistance, means for closing the same across the armature after the main motor circuit is broken, and a doubly-wound electromagnet connected to control said resistance, one of the coils of said magnet being slower acting than the other, substantially as set forth.

12. The combination with a motor, of a variable resistance, and means for closing the circuit of the same around the motor-armature after the main motor-circuit is broken, and a differentially-wound magnet controlling said resistance having one of its coils slower acting than the other, substantially as described.

13. The combination with a motor, of an armature-circuit containing resistance, means for closing said circuit after the main motorcircuit is broken, and an electromagnet controlling said resistance provided with differentially-wound series and shunt coils, and a plurality of coils and armatures, the shunt-coil being slower acting than the series coil, substantially as described.

1 1. The combination with a motor, of means for gradually bringing the same to a stop, consisting of an armature-circuit normally containing resistance, means for closing the said circuit after the main motor-circuit is broken, and an electromagnet for gradually reducing said resistance, substantially as described.

15. The combination with a motor, of a manual switch, an electromagnetic reversingswitch, connections for operating the revers- In testimony whereoflhavesigned my name ing-sWitch from the manual switch, starting to this specification in the presence of tWo subp resistance for the motor, a controlling-magnet scribing Witnesses. operated by line-potential, and means con- JOHN D. IHLDER. 5 trolled by Variations of motor-current for vary- Witnesses:

ing the strength of said controlling-magnet, C. B. MANVILLE, substantially as described. I F. WV. NEWELL. 

